NO. 29 



VOLCANOES AND CLIMATE ABBOT AND FOWLE 



21 



greater than would be caused directly by the darkening of the sun 

 by sun-spots, so that it is supposed that there is accompanying the 

 spots some secondary influence affecting terrestrial temperatures. 

 General fluctuations of temperature have also occurred which are 

 not fully accounted for by the march of the sun-spots. We have 

 endeavored to see whether a combination of the sun-spot influence 

 with the effect of the volcanic haze on solar radiation will produce 



Table 6. Temperature Departures 1 191 2. Cloudless Regions, 

 United States. 



Station. 



Leadville, Colo. . . 

 Flagstaff, Ariz.. .. 

 Tucson, Ariz 



Pueblo, Colo 



Dodge, Kans 



Santa Fe, N. Mex 

 El Paso, Tex 



Month. 



Jan. Feb. March. April. May. June 



+0.5 

 + 1.6 



+0.7 



— 2.0 

 + 1.8 

 — 1.6 



-0 . 6 ] —4 . 1 

 -1.7 —4.0 

 -2.9 I — 6. 



-0.5 

 -1.9 

 -2.4 



—2.7 

 —0.9 



+ 1.1 



Mean. 



—1.57 

 -O.85 

 —1.98 



—2.55 

 —3.93 

 —1.93 



-1.65 



1 Fahrenheit Scale. 



a more exact correspondence between the solar phenomena and the 

 temperature of the earth. 



Referring to Fig. 3, the curve A is a smoothed representation of 

 the average intensity of the direct solar radiation. The method of 

 smoothing the curve is as follows, taking for example the year 1895 : 

 Add to the value for 1894 twice that for 1895 and that for 1896, 

 and divide by 4. Curve B is the smoothed sun-spot curve as given 

 by Wolfer. The sun-spot numbers run from to about 80. Curve 



